International Master (IM) is the FIDE chess title one step below Grandmaster.
The requirements mirror the GM title at a lower level: IM norms (usually three, with a performance of at least 2450) and a FIDE rating of at least 2400. It can also be awarded directly, for example for a silver or bronze medal at the World Junior Championship U20.
The women’s version is WIM (Woman International Master), which requires a 2200 rating.
Related terms: Grandmaster · FIDE Master · Chess titles (article)